There is a shortage of human corneal tissue for transplantation with many patients waiting 6 months or longer to have sight restoring surgery. The Eye Banks International arbitrarily rejects all corneas that have been procured more than 12 hours after death or those that have been stored in M-K medium for more than 72 hours. Although Eye Banks International processed over 10,000 corneas last year, the standards including time limits for procurement and preservation limited the number of surgical corneas to 4,000. By increasing the procurement and preservation times, an estimated 2,000 additional surgical corneas would be available for transplantation. We studied the effect of extended death-to-enucleation and preservation time on the glycolytic activity of media stored rabbit and human corneas. We have found that glycolytic activity is markedly decreased at 24 hrs. death-to-enucleation and was found to be nil at 48 hrs. Corneas preserved 72 hours in M-K media at 4 degrees C demonstrated significantly decreased activity particularly when combined with 7 and 24 hrs death-to-enucleation times. Recently, we have demonstrated the feasibility of utilizing 13C-NMR spectroscopy to monitoring glycolytic activity in human and rabbit corneas. This technique enables the non-invasive quantification of metabolic activity in a cornea such that subsequent transplantation is possible. This study is designed to study the feasibility of NMR spectroscopy to quantitate glycolytic activity in the cat cornea as a prediction for successful penetrating keratoplasty. Progressively increasing death-to-enucleation times combined with increased preservation times will be studied. If successful, this pilot project will become the model on which 13C-NMR studies of human donor tissue will be based. This impact of this study could be far reaching by providing an index of corneal viability and a more precisely defined time limit of procurement and preservation of human donor corneal tissue.